(1) Field of the Invention
This application relates to climate and environmental management systems, specifically to improve exergy flows, system entropy level, and resource utilization.
(2) Description of Related Art
From early history, mankind has altered his environment to harness inputs from the surroundings and provide a more suitable environment. Plantings such as hedgerows blocked wind. Swales retained water for plants. Chinampas created optimal environments for agricultural production. Fog-fences and air-wells dehumidified the air and provided water. Buildings were oriented to moderate solar radiation and high thermal mass walls captured the day's heat to be released at night. Controlled fires provided supplementary heat. Windmills captured the wind's energy and paddle-wheels captured energy from flowing water. With the advent of translucent glazing, greenhouses found new ways of utilizing solar radiation to further moderate climate. With the discovery of fossil fuels and the beginning of the industrial revolution came new methods of climate, device, and process control as well as the creation of the current heating, ventilation, and air conditioning (HVAC) industry.
The majority of these modern climate control techniques utilize large inputs of energy and are limited in scope to the services they provide (typically heating, cooling, ventilation, and humidity control). Improvements to these systems have happened incrementally and typically continue to only address these areas of climate control.
There are numerous prior arts that are referenced above that showcase many of these types of solutions for improvements to climate control. Almost all of these designs focus on a single design goal: energy conservation. A few designs, some for research and space applications, such as U.S. Pat. No. 5,322,035 to Hawes et al. 1994, for a Hydrological System for a Closed Ecological System, Cullingford, U.S. Pat. No. 5,005,787, Yang, U.S. Pat. No. 5,614,378, [closed ecological life support system (CELSS)] showcase other aspects of climate management. These patents address conditions within a sealed environment and include additional conservation parameters not typically associated with managing climates including managing available resources through nutrient, carbon, and water cycles. By expanding design focus beyond the single design goal of energy conservation into efficient resource utilization, a new approach for environmental management becomes possible.
Some of these new approaches were developed at the New Alchemy Institute in New England by Dr. John Todd and his group, which would later include assistance from William Irwin Thompson, Amory Lovins, and Buckminster Fuller. They did pioneering work with their experimental self-sufficient structure, “The Ark”, in the early 1970s. This group was one of the first to emphasize aquaculture in self-sufficient home designs. Dr. John Todd later went on to develop “Living Machines”, biological processes that remediate wastewater.
Arguably the best known sealed-environment project was the large Biosphere II structure in Arizona that completely sealed in eight people for two years beginning in 1991. It enclosed approximately three acres under glass, about half an acre of which was dedicated to food production using 156 edible plant species. This structure cost around $150 million to construct for a per square foot cost of around $1,100 making it unaffordable for anything but scientific research. The experiment formed the most in-depth documentation on efficient food self-sufficiency in a confined space at that time. The Biosphere II included a mountain, a savanna, a rain forest, a desert, an ocean and many other different climates in one huge glass structure. It was reported that these climates required air conditioning and air movement resulting in extremely large use of externally sourced energy. In addition, if the structure were to be without power for extended periods of time, the temperature rise would kill off most of the plants and animals.
Other types of environmental climate control systems that focus on self-sufficiency and resilience have been develop in the United States such as the attached greenhouse and the envelope home. One of the most widely known of greenhouse homes is the ‘earthship’ developed by architect Mike Reynolds. These low-resource input homes are built with recycled materials-predominantly automobile tires with rammed earth that provides thermal mass for passive climate control. These systems incorporate many water and energy-conserving techniques and are often built with significant food-producing capabilities.
A lesser known climate control system is that of Greenhouse Village in The Netherlands. The design of Greenhouse Village (Zonneterp in the Dutch language) consists of energy-producing greenhouses. These energy producing greenhouses increase vegetable harvests by 20% while completely eliminating fossil fuel use. The Greenhouse Village is one of the first systems to enable a completely decentralized solution for providing energy, recycling nutrients, and provide waste and wastewater treatment.
The idea of the vertical farm has become well-known in recent years as offering the possibility of food production in crowded city areas. As none have been built, the actual functionality and practicality is relatively unproven. Obvious problems relate to the fact that farming sky scrapers may experience shade for most of the day from the other nearby buildings. Also, while photosynthesis harvests energy from the sun, there is only so much sunlight per unit area of land —vertical stacking doesn't change that.
The closest in possible function to the embodiments described within this document is the Dream Farm concept by George Chan—although it is dependent upon and restricted by local climatic conditions. The Dream Farm concept has been updated to the Dream Farm-2 concept by Mae-Wan Ho. This proposed model of an integrated, “zero-emission”, “zero-waste” highly productive farm maximizes use of renewable energies and turns waste into food and into energy resources without utilizing fossil fuels.
In reviewing existing patents, a good place to start is US 20080000151 which typifies the problems and responses of current art to the problems of managing a plant growing environment. Solutions for managing temperature levels include exchanging airflows between the outside and inside atmospheres. This is accomplished using active controls such as fans and a gas-fed heating system supplemented with a water thermal-storage reservoir that captures heat as it cools the environment. Later it releases this heat as required. When the greenhouse reaches desired temperature levels, air is recirculated within the systems.
There are numerous problems and liabilities of such a climate control system. The first is predicated on exchange of outside air that may contain undesirable atmospheric pollutants or pests that may adversely affect internal growth processes. Additionally, the recirculation of atmospheric gas ratios may be adversely affected by the internal air circulation as autotrophs (plants) consume all the CO2 during respiration. Another problem is that of varying external environmental conditions. While equipped with a gas-heater for periods of cold, the thermal-storage reservoir does little to provide cooling when the coupled outside environment is continually warm. Also these systems presuppose outside inputs of fossil fuels and electricity in order to function.
A patent that addresses some of these issues is U.S. Pat. No. 4,077,158. This patent reflects many of the complex issues behind providing environmental control for a growing environment.
In this patent, it offers a way to utilize a reversible thermosiphon to exchange heat with a hot and cold thermal-storage reservoir. The hot reservoir also has provisions to capture the suns radiation. It also incorporates rainwater harvesting that may also affect the temperature levels of these thermal-storage reservoirs. The growing system offers several features such as segregation and filtration of the internal atmosphere to exclude pests. The reservoirs are multi-function and can act as a moat to transport vegetation grown within the system. The reservoirs also support aquaculture. It also supplements the possible cooling offered by the thermal-storage reservoir by directly irrigating plants to provide evaporative cooling and remove heat. It also goes even further in controlling the environment for the plants by aerating their roots and providing water and nutrients as needed.
These same problems, and solutions will be reviewed in the following discussion on the exergy and resource environmental management system. Before that discussion, it's useful to first look at some other technologies that may be useful in addressing these issues.
The first of these technologies is using bodies of water as a thermal reservoir, in patent 20070295489. This patent's major innovation is tapping previously unused thermal reservoirs such as swimming pools and reservoirs for fire suppression in order to reduce air conditioning expenses. It goes on to discuss how to do a heat exchange so that the fluid within the reservoir doesn't mix with the reservoir. It also goes on to discuss how to alter the temperature of the thermal reservoir to stay within desired parameters, basically consisting of using power at non-peak times. Problems with this design include the need to continually thermally condition the reservoir with active processes. In addition, it offers no remedy to keep bodies of water, such as swimming pools, at a constant desired temperature without active inputs of energy. Solutions to address these issues will be discussed.
Another interesting patent that showcases relevant technology for environmental controls is U.S. Pat. No. 7,997,079, which is the use of a thermal gradient within a sensible heat thermal reservoir. While the temperature gradient is very useful, it does suffer potential problems of mixing of the medium. The thermal energy carrier fluid also only travels from one reservoir to a client through the use of active sensors. Other problems are that it only offers a hot and cold bank. An alternative design will be proposed that addresses these limitations.
In patent WO 2013070396 A1, another interesting technology is introduced. This is quite possibly the first published patent to discuss the advantages of thermal storage in a cascading array. This technology was primarily created to address the issues of storing the thermal energy of a concentrating solar array. The interesting technology to environmental management is the use of phase change materials for the storage of heat, and how the cascade of one charged phase change material then charges the next. This has many benefits, but doesn't address being able to use sensible storage techniques in addition to latent heat isothermal buckets.
(3) Other References
Not Included